Neutralized vinegar concentrates and liquid food grade blends containing said neutralized vinegar concentrates

ABSTRACT

The present invention is directed to a process for making a concentrated vinegar product by simple evaporation, which concentrated vinegar product can also be used as intermediate in the production of products that can be listed on food labels as “vinegar”.

FIELD OF THE INVENTION

The present invention concerns the field of liquid, concentrated foodpreservation products, in particular concentrated vinegar products. Thepresent invention provides a method of producing highly concentratedvinegar, enabling the production of food-grade liquid preservationproducts comprising high amounts of vinegar. Such liquid preservationproducts and their uses are also encompassed by the invention.

BACKGROUND OF THE INVENTION

Vinegar is a term used to denote a sour liquid with acetic acid as themain component that has been widely used in domestic cooking for ages asa condiment, a preservative, a flavorings ingredient, etc. Thepreparation of vinegar is one of the oldest food production methods ofmankind and involves the oxidative fermentation of ethanol, primarilyobtained from plant material, by acetic acid bacteria (AcetobacterAceae). It is a time-consuming production process, comparable in certainaspects to wine making. The composition of vinegar can be quite complexand varies depending on the starting material, some examples includingvinegar from alcohol (e.g. white vinegar, brandy vinegar, alcoholicvinegar, balsamic vinegar), wine vinegar (made from wine, excess wine orwaste wine), vinegar made from floury substances (e.g. malt vinegar,beer vinegar, cane vinegar, potato vinegar, rice vinegar) and fruitvinegar (made from fruit juice, e.g. apple vinegar, cherry vinegar,banana vinegar). Major vinegar components, besides acetic acid, includeother organic acids (mainly gluconic, malic, tartaric, succinic acids)and sugars (mainly glucose and fructose). Classes of minor componentsinclude volatile compounds and antioxidant molecules, mainlypolyphenols. Such minor components are important to the flavor and aromaof the vinegar.

According to food regulations in Europe and the United States the term“vinegar” can be used only to denote liquid products obtained by theacetous fermentation of an alcoholic liquid and containing a minimumpercentage of acetic acid, usually at least 4 or 4.5%.

When vinegar is used as an ingredient in industrial food processing itcan be listed on the label simply as “vinegar”, rather than the chemicalname, acetic acid. This is a big advantage for Industrial foodprocessors, as consumer aversion against chemically descriptive words onthe list of declared ingredients on food labels is growing considerably.Thus, food processors are trying to remove ingredients that may not beconsidered “label friendly” and substituting ingredients that can beconsidered natural. Ideally, processors would like to have an “allnatural” declaration on the label. Because vinegar has been used indomestic cooking for ages, it has the generally regarded as safe (GRAS)status and ‘consumer acceptance’ is still high.

At the same time, industrial food processors are seeking to obtain moreconcentrated forms of vinegar. One obvious advantage of using moreconcentrated products is that it reduces the volume of the product to beapplied to accomplish a certain (anti-microbial) effect. Moreconcentrated forms are also advantageous with regard to transportationand storage. Furthermore, concentrated vinegars can be blended withother food grade compositions to produce new liquid food preservationproducts.

It has proven technologically challenging though, to develop methods forprocessing vinegar into concentrated products meeting all the demandsimposed by food processors in terms of quality, stability and regulatoryrequirements. Many dilute substances may be concentrated by simpleevaporation, but with vinegar this is not feasible because of therelatively close boiling points of water and acetic acid (even thoughthe two do not form an azeotrope) and of the relatively low flash pointof acetic acid (i.e. the temperature at which it can vaporize to form anignitable mixture in air). Fractional distillation processes have beendescribed in the art, for example in U.S. Pat. No. 3,002,896, but theseprocesses are unattractive from an economical point of view. As a matterof fact, to date no commercial concentrated vinegars are produced byevaporation or distillation techniques.

The technique nowadays most often applied in the production ofconcentrated vinegar is “freeze concentration”. This technique involvesfreezing at least a portion of the aqueous part and separating the icefrom the remaining liquid. U.S. Pat. No. 4,076,844 refers to a processin which vinegar of lower acidity is subjected to freezing. The ice soformed contains very little acid and is removed by centrifugation,leaving the desired higher acidity vinegar, having an acetic acidconcentration of 20 percent weight by volume or more. Freezeconcentration is also mentioned in U.S. Pat. No. 4,313,960, whichdescribes a process for the preparation of vinegar by freezeconcentration, stating that the essential condition to obtain anacceptable product is to add ethyl alcohol to the vinegar. Preferably,the vinegar/ethanol mixture is made to pass over ion exchange resins toimprove the flavour of the vinegar. Freeze concentration has its limitsin terms of maximum concentration that can be attained, due to theincreased viscosity at freezing temperatures. Separation of ice fromviscous concentrated products becomes more and more difficult as theconcentration increases until eventually no further concentration effectcan be achieved. Apart from these limitations, the process is inherentlyexpensive because it requires a large investment in machinery andentails high operating costs in the form of electrical energy and manpower. The addition of components such as ethylalcohol is undesirablewith a view to application of the product as a food ingredient.

GB-B-1,101,560 and U.S. Pat. No. 4,076,844, for example, mention freezeconcentration as a known technique for producing concentrated vinegar,but underline how this technique is costly and unfavourable. In view ofthese limitations, the use of a particular acetic fermentation technique(so-called submersed fermentation) to obtain vinegar with a high degreeof acidity is advocated. U.S. Pat. No. 4,076,844, describes a two-stagefermentation process according to which vinegar with an acetic acidconcentration between 16 and 17 percent weight by volume was obtained.Clearly, this process is also quite cumbersome, whereas the highestpossible acetic acid concentration in the vinegar is still not higherthan 17%.

According to NL7609825, vinegar is concentrated by contacting it with ahydrate forming substance, such as trichlorofluoromethane ordichloromethane, at a temperature below the maximum temperature at whichthe hydrate is formed. Thereafter the hydrate formed is separated fromthe concentrated vinegar and any formed solid vinegar, for example bysublimation or dissolution of solid hydrate under such conditions, thatsolid acetic acid is not sublimed or dissolved and is not denaturated.In this way vinegar having a concentration up to 80% by weight of aceticacid can be obtained. However, this process has the disadvantage thatthe hydrate forming substances can only be removed with high costs fromthe concentrated natural vinegar, whereas the characteristic aromaticconstituents are lost completely or substantially completely. Theaddition of components such as trichlorofluoromethane or dichloromethaneis problematic, at least with a view to application of the product as afood ingredient.

More recently, in WO 2007/035244, a process for producing concentratedvinegar was described based on simple evaporation after completeneutralization of the vinegar with sodium bicarbonate. The neutralizedvinegar is concentrated by evaporation until a thin layer of crystallinematerial is formed on the surface of the material. To this concentrate,a certain amount of vinegar is added back in an amount resulting in 10to 20% excess of acetic acid salt over free acid. A problem encounteredin the process according to WO 2007/035244 is that the sodium acetatetends to crystallize out of solution, so that the concentratedneutralized vinegar should not be allowed to cool down. For the samereason the vinegar mix, i.e. the product obtained after adding backvinegar, should not contain more than 45% of acetic acid/acetate salt.

It is not surprising, given the above, that the most concentrated formof vinegar commercially available to date is 300 grain, whichcorresponds to a total acidity, based on acetic acid, of approximately30%.

It is an object of the invention to prepare a concentrated naturalvinegar product without the disadvantages of the known processes. It isan objective of the present invention to provide a concentrated naturalvinegar product that has good microbiological and physical stability andcan be labeled as vinegar in (industrial) food processing.

SUMMARY OF THE INVENTION

The present inventors found a way to obtain an excellent concentratedvinegar product by simple evaporation, which concentrated vinegarproduct can be used as intermediate in the production of products thatcan be listed on food labels as “vinegar”, thereby realizing anobjective of this invention.

An essential element of the present invention resides in theneutralization of the vinegar with an alkalizing agent comprisingcationic potassium. The present inventors found that potassiumneutralized vinegar behaves significantly more favorable than sodiumneutralized vinegar under the conditions typically applied in theprocess of concentrating by evaporation.

Hence, the invention in particular pertains to a process of producing aneutralized vinegar concentrate, to the neutralized vinegar concentratethus obtained, to blends of the neutralized vinegar concentrate withother food grade ingredients, in particular other food grade organicacids, to the application of the neutralized vinegar concentrate and theblends of this invention in the preservation of food products and to thefood products thus obtained.

These and other aspects of the invention will be explained in moredetail in the following description and illustrated in the appendingexamples.

DETAILED DESCRIPTION OF THE INVENTION

A first aspect of the invention concerns a Process of producing aneutralized vinegar concentrate, said process comprising the steps of:

a) providing a liquid vinegar;b) adding an alkaline potassium compound to said liquid vinegar toproduce a neutralized vinegar having a pH of at least 6; andc) concentrating said neutralized vinegar to a dry solids level of above50% (w/w) by evaporation.

In this document, the term vinegar is used to denote the liquid obtainedby the acetous fermentation of an alcoholic liquid, containing at least4 grams of acetic acid per 100 ml, in particular a vinegar that can bedeclared ‘natural’, e.g. in terms of the FDA guidelines. According tosaid guidelines “natural” means minimally processed and containing nosynthetic ingredients or processing aids (cf. Food Labeling: NutrientContent Claims General Principles, Petitions, Definitions of Terms, 56Fed. Reg. at 60,466).

In a preferred embodiment step a) comprises providing a vinegar selectedfrom the group consisting of white vinegar, brandy vinegar, alcoholicvinegar, balsamic vinegar, wine vinegar, malt vinegar, beer vinegar,potato vinegar, rice vinegar, apple vinegar, cherry vinegar, and canevinegar. In a particularly preferred embodiment of the invention, thevinegar is cane vinegar.

In a preferred embodiment of the invention, the acetic acid content ofthe vinegar is at least 5% (w/w), more preferably at least 7.5% (w/w),even more preferably at least 10% (w/w). It is also possible to make useof vinegar that has been pre-concentrated to a certain extent. Suchproducts are commercially available and typically have an acetic acidcontent between 20 and 30% (w/w). In a preferred embodiment of theinvention, the acetic acid content of the vinegar is at least 20% (w/w),more preferably at least 25% (w/w), e.g. about 29 or 30% (w/w). A commonmeasure for indicating the acetic acid content of vinegar is the grainstrength. The grain strength is the acetic acid content expressed ing/l, so 50 grain vinegar is about 5% (w/w) acetic acid. As will beappreciated by those skilled in the art, it is preferred that thevinegar is at least 200 grain, more preferably at least 250 grain.Often, commercial food-grade vinegars are offered at 200 grain and 300grain. In one preferred embodiment of the invention, a 300 grain vinegaris used.

Step b) of the process of this invention comprises adding an alkalinepotassium compound. Alkalinity, as used herein, refers to the capabilityof the compound to lower the amount of protons in a solution to anyextent and, hence, increasing the pH value. It does not necessarilyimply an increase of the pH to above neutral. The term “alkalinepotassium compound” means an organic or inorganic compound containingcationic potassium, which reacts with an acid to accept hydrogen atomsand/or donate a pair of valence electrons, and, as such, can be added tothe vinegar to neutralize it to the desired extent. Examples of thealkaline potassium compounds in accordance with the invention includepotassium hydroxide, potassium carbonate and potassium bicarbonate. In apreferred embodiment of the invention the alkaline potassium compound ispotassium hydroxide.

In one embodiment of the invention, the process comprises addition ofpotassium hydroxide, especially the addition an aqueous solutioncontaining at least 100 g/l of potassium hydroxide, more preferably atleast 250 g/l of potassium hydroxide, more preferably at least 500 g/lof potassium hydroxide.

It is envisaged that other alkaline compounds may be used in conjunctionwith potassium hydroxide. For example, other alkali or earth alkalimetal hydroxides, such as sodium and/or calcium hydroxide, may be addedin addition to the alkaline potassium compound.

In case other alkaline compounds are added besides the alkalinepotassium compound, it is preferred that at least 50% of the total molamount of the cations added is potassium, more preferably at least 60%,at least 70%, at least 80%, at least 90%, or at least 95%.

In one particular embodiment of the invention, step b) comprises theaddition of an alkaline potassium compound, preferably potassiumhydroxide, and an alkaline sodium compound, preferably sodium hydroxide,in a (mol/mol) ratio of above 3/1, preferably within the range of3/1-100/1.

In a preferred embodiment of the invention, step b) comprises adjustingthe pH value of the vinegar to a value within the range of 6-10, morepreferably to a value within the range of 7-9, most preferably to avalue within the range of 7.5-8.5

In a preferred embodiment of the invention, step b) comprises addingalkaline compound to the vinegar in an amount sufficient to accomplish adegree of neutralization of at least 50%, more preferably at least 60%,more preferably at least 70%, more preferably at least 80%, morepreferably at least 90%, more preferably at least 95% and mostpreferably at least 99%. The ‘degree of neutralization’, as used herein,is a parameter expressing the amount of carboxyl groups present in thesalt form relative to the total number of carboxyl groups, which can beequated as follows: (—COOM groups)/(sum of —COOM groups and —COOHgroups)(*100 percent), where the —COOM groups represent a salt formedbetween an acetate carboxyl group and a cation.

In an embodiment of the invention, the alkaline potassium compound andthe vinegar are combined in such (relative) amounts that the (mol/mol)ratio of potassium cations to acetate anions in the solution is morethan 0.5/1, preferably more than 0.6/1, more preferably more than 0.7/1,more preferably more than 0.8/1, more preferably more than 0.9/1, morepreferably more than 0.95/1, most preferably more than 0.99/1.

In case other alkaline compounds are used besides the alkaline potassiumcompound, it is preferred that they are added in amounts providingcations in a total amount of potassium and other alkaline compounds inexcess of 50% of the stoichiometric equivalent. The term “stoichiometricequivalent” as used herein to quantify the relative amount of cations inthe composition, means the amount necessary to provide counterions forall acetate ions present in the vinegar. Hence, an amount of 50% of thestoichiometric equivalent refers to an amount providing counterions for50% of the acetate anions. As will be understood by those skilled in theart, the stoichiometric equivalent for monovalent potassium cationsequates to a 1:1 molar ratio of acetate and potassium ions, while thestoichiometric equivalent of acetate and divalent calcium cations wouldequate to a 2:1 molar ratio, which also means that a 2:1 mixture ofcalcium and potassium cations (on the basis of mol amounts) in astoichiometric equivalent will comprise acetate, Ca²⁺ and K⁺ in a molarratio of 5:2:1. In a preferred embodiment of the invention, alkalizingagent is added in an amount providing metal cations in a total amount inexcess of 60% of the stoichiometric equivalent, preferably in excess of70%, in excess of 80%, in excess of 90%, in excess of 95%, or in excessof 99% thereof.

In accordance with the present invention, the neutralized vinegarobtained in step b) is subjected to a process resulting in the removalof water, typically by evaporation. The invention is not particularlycritical as to the type of evaporation process used. Typically, however,step c) of the present method will involve heating of the neutralizedvinegar to above room temperature and/or the application ofsub-atmospheric pressure.

In a preferred embodiment of the invention, step c) comprises heating ofthe neutralized vinegar to a temperature within the range of 20-120° C.,more preferably to a temperature within the range of 40-110° C., mostpreferably to a temperature within the range of 60-100° C.

In a preferred embodiment of the invention, step c) comprises heating ofthe neutralized vinegar while keeping the neutralized vinegar underreduced pressure.

The person skilled in the art will be able to select the appropriateequipment and to perform such a process on the basis of common generalknowledge and applying routine skills. As exemplary embodiments, the useof a rising or falling film evaporator, or a batch pan may be mentioned.In a preferred embodiment of the invention, step c) comprisesconcentrating the neutralized vinegar obtained in step b) in a fallingfilm evaporator apparatus, operated at the above indicated temperaturesand pressures.

Preferably, step c) comprises concentrating said neutralized vinegar toa dry solids level of above 50% (w/w), as indicated before, morepreferably to a dry solids level within of above 55% (w/w), morepreferably to a dry solids level of above 58% (w/w), most preferablyabove 60% (w/w). Preferably, step c) comprises concentrating theneutralized vinegar until a dry solids level within the range of 50-70%(w/w) is reached, more preferably until a dry solids level within therange of 60-65% (w/w) is reached.

Preferably, step c) comprises concentrating said neutralized vinegar toan acetate salt level of above 50% (w/w), e.g. at least 50.1% (w/w); atleast 50.5% (w/w); at least 51% (w/w); or at least 52% (w/w). Morepreferably, step c) comprises concentrating said neutralized vinegar toan acetate salt level of above 55% (w/w), more preferably above 58% w/v,most preferably above 60% (w/w). Preferably, step c) comprisesconcentrating said neutralized vinegar to an acetate salt level withinthe range of 50-70% (w/w), more preferably within the range of 60-65%(w/w).

The term ‘acidity’ is also often used to characterize the type ofproducts of this invention. In this context, the term “total acidity” isused to denote the total amount of organic acids in salt form and inacid form per unit of volume of the product. “Total acidity” can e.g. beexpressed in mmol of acid per 100 g of the product. Total acidity canalso be expressed as a weight percentage, on the basis of the acid(molar) weight(s). For example, a completely KOH neutralized vinegar,concentrated to a 60% (w/w) potassium acetate concentration would have atotal acidity of 611 mmol per 100 g, or, based on acetic acid, ofapproximately 36% (w/w). When different types of organic acids arepresent, total acidity is the sum of the total acidities per organicacid (for this the total acidities of per single acid have to beknown/determined).

The term “free acidity” is used to denote the amount of organic acids inacid form per unit of volume of the product. Free acidity can e.g. beexpressed in mmol of acid per 100 g of the product. “Free acidity” canalso suitably be expressed as a (weight) percentage of free acidrelative to the total weight of the composition.

Free acidity and total acidity can be assessed by means ofpotentiometric titration which is a routine method for those of averageskill in the art.

Preferably, step c) comprises concentrating the neutralized vinegaruntil a total acidity of above 500 mmol/100 g is reached, morepreferably until a total acidity of above 550 mmol/100 g is reached,more preferably until a total acidity of above 580 mmol/100 g isreached, most preferably until a total acidity of above 600 mmol/100 gis reached. Preferably, in step c) the neutralized vinegar isconcentrated to a total acidity within the range of 500-700 mmol/100 g,more preferably to a total acidity within the range of 600-650 mmol/100g is reached.

The concentrated neutralized vinegar produced in accordance with theabove-described process typically is in the form of a liquid, as will beunderstood by those skilled in the art, e.g. based on thecharacteristics as described here above. More in particular, theconcentrated neutralized vinegar produced in accordance with theabove-described process typically is in the form of a solution.

It is one particular advantage of the present invention that theconcentrated neutralized vinegar as produced in accordance with theabove-described process is relatively stable and, in particular, can bekept at ambient temperatures, or even at temperatures below 10° C. ornear 0° C., without acetate salt crystallizing out of the solution inany appreciable amount. Moreover, since the water activity of theconcentrated neutralized vinegar is relatively low, the product is alsomicrobiologically stable at ambient temperatures. Hence, an embodimentof the present invention is envisaged where the concentrated neutralizedvinegar is allowed to cool down. Preferably the concentrated neutralizedvinegar obtained in step c) is allowed to cool down to a temperaturewithin the range of 0-35° C., more preferably to a temperature withinthe range of 0-30° C., most preferably to a temperature within the rangeof 0-25° C. In an embodiment of the invention, the process comprisesplacing and keeping the concentrated neutralized vinegar in a tank withcooling means, such as a double wall or a tubular or plate heatexchanger to cool it to a temperature as indicated above. In anembodiment of the invention, the product is allowed to cool down simplyby storage under ambient conditions.

The product obtained as described in the foregoing can be used as suchin e.g. food processing. Nevertheless, in a preferred embodiment of theinvention, the concentrated neutralized vinegar is subjected to furtherprocessing steps in order to produce products that can be listed as“vinegar” or containing “vinegar”.

An aspect of the invention concerns a process of producing a liquid foodpreservation product, comprising the process of producing a neutralizedvinegar concentrate as defined in the foregoing, followed by the stepsof:

d) providing a further composition comprising one or more organic acidsand/or organic acid salts; ande) combining said concentrated neutralized vinegar and said furthercomposition comprising one or more organic acids and/or organic acidsalts to obtain a liquid food preservation product.

In the application of the liquid food preservation product, the productof the invention has the advantage that the dosage levels can be low dueto the high concentration of vinegar. In one embodiment, said furthercomposition comprising one or more organic acids and/or organic acidsalts is selected so that dilution of the neutralized concentratedvinegar as a result of step e) is minimized. Hence, in an embodiment ofthe invention said further composition has a high dry solids content,e.g. above 10% (w/v), above 20% (w/v), above 30% (w/v), or above 40%(w/v).

In one embodiment of the invention, a process as defined herein beforeis provided, wherein step d) comprises providing a second liquidvinegar. Preferably said second liquid vinegar is a vinegar of 200-300grain. Preferably said second liquid vinegar is a crude vinegar. In aparticularly preferred embodiment of the invention the vinegars providedin steps a) and d) are the same type and (grain) strength. As will beunderstood by those skilled in the art, this embodiment results in a(concentrated) product comprising acetate in partially neutralized form.

In a particularly preferred embodiment of the invention, the secondliquid vinegar is combined with the concentrated neutralized vinegar inan amount resulting in a free acidity of at least 3.5 g/100 ml, morepreferably at least 4 g/100 ml, most preferably at least 4.2 g/100 ml.Products produced in accordance with this embodiment of the inventioncan be listed as “vinegar” and/or as “natural”.

In one embodiment of the invention, a process as defined herein beforeis provided, wherein step d) comprises providing a compositioncomprising a lactate component and/or a propionate component and/or acitrate component. The terms lactate component, propionate component andcitrate component as used herein encompass the respective acids as wellas salt forms of the respective acids, as will be understood by thoseskilled in the art.

As will be understood by those skilled in the art, embodiments areenvisaged wherein a lactate component and/or propionate component and/ora citrate component is added as a highly purified product. Such highlypurified products are available commercially and it is, additionally,within the common general knowledge and capabilities of those of averageskill in the art to produce such products.

In a preferred embodiment of the invention however, step d) comprisesproviding a crude or only partially purified/clarified lemon juicecomposition, comprising a citrate component. Crude or partiallypurified/clarified lemon juice may confer favorable organolepticprofiles, which contribute positively to the taste and flavourcharacteristics of food products to which they are added. Moreover, suchproducts will provide additional benefits with regard to labeling andregulatory aspects. In one embodiment, a lemon juice concentratecontaining at least 30% w/w) of a citric acid component, preferablycitric acid and/or a citric acid salt, is provided in step d), morepreferably at least 35% (w/w), most preferably at least 40% (w/w). In anembodiment a solid composition comprising lemon juice solids is providedin step d). Lemon juice concentrate and solid compositions containinglemon juice solids are commercially available. Preferably at leastpartially neutralized lemon juice concentrate or solid compositionscomprising lemon juice solids are provided, characterized by a pH valuewithin the range of 4-9, more preferably within the range of 5-8, mostpreferably within the range of 6.-7.6

In another preferred embodiment of the invention, step d) comprisesproviding a crude or partially purified/clarified ferment, referred toherein as ‘fermentation product’, comprising a lactate component and/orpropionate component. Such crude or partially purified/clarifiedferments have very favorable organoleptic profiles, which contributepositively to the taste and flavour characteristics of food products towhich they are added. Moreover, such fermentation products will provideadditional benefits with regard to labeling and regulatory aspects.

As used herein the term ‘fermentation product’ refers to a compositionthat is obtainable by fermentation of a fermentable substrate with asuitable microorganism, in this case a lactic acid and/or propionic acidproducing microorganism, resulting in a composition typicallycomprising, besides the lactic acid or propionic acid component, tracesof the fermentable substrate, other substances produced by themicroorganism, and traces of the microorganism itself, e.g. cellulardebris and/or cellular components. The lactic acid and/or propionic acidproducing micro-organisms may also produce other preservative compoundssuch as nisin or other bacteriocins, acetic acid, succinic acid, etc. Assuch, a liquid fermentation product is distinguishable from e.g. highlypurified products. The term however does not exclude products which havebeen subjected to some form of purification/clarification and/orconcentration.

In one embodiment, the fermentation product is the supernatantobtainable by fermentation of a fermentable substrate with a lactic acidor propionic acid producing microorganism followed by separatingsupernatant from (wet) biomass and other solid particles.

In one embodiment of the invention, the fermentation product is aconcentrated supernatant obtainable by fermentation of a fermentablesubstrate with a lactic acid or propionic acid producing microorganismfollowed by separating supernatant from (wet) biomass and other solidparticles and concentrating the supernatant.

In one embodiment of the invention the fermentation product is apartially purified and optionally concentrated supernatant obtainable byfermentation of a fermentable substrate with a lactic acid or propionicacid producing microorganism followed by separation of supernatant from(wet) biomass and other solid particles, purification of the supernatantand, optionally, concentration of the supernatant, with the proviso thatthe purification does not result in a level of the lactate component orpropionate component of more than 97 wt % on a dry solids weight basis,preferably it does not result in a level of the lactate component orpropionate component of more than 96 wt % on a dry solids weight basis,most preferably it does not result in a level of the lactate componentof more than 95 wt % on a dry solids weight basis.

As will be clear to those skilled in the art, the fermentation productcomprises other dispersed or dissolved solids besides the lactate orpropionate component. Typical examples of such other dispersed ordissolved solids include sugars, such as lactose, glucose and sucrose;other organic acids and/or salts thereof, such as citric acid, pyruvicacid, malic acid, succinic acid, formic acid and acetic acid; nitrogencontaining substances, such as amino acids, peptides and proteins;nucleic acid components such as DNA and RNA fragments, nucleotides andnucleosides; cell membrane phospholipids; vitamins; trace elements; andpigments. In a preferred embodiment of the invention the liquidfermentation product comprises at least one, at least two, at leastthree, at least four or at least five components selected from the groupconsisting of lactose, glucose, sucrose, citric acid and salts thereof,pyruvic acid and salts thereof, malic acid and salts thereof, succinicacid and salts thereof, formic acid and salts thereof, acetic acid andsalts thereof, amino acids, peptides and proteins.

The liquid fermentation product, in accordance with a preferredembodiment has a pH value, when diluted with water to a 10% (w/w) solidslevel, within the range of 4-9, more preferably within the range of 5-8,most preferably within the range of 6-7.6

In a particularly preferred embodiment of the invention, a process asdefined herein is provided, wherein step d) comprises:

d1) providing a nutrient medium comprising a solution of a fermentablesubstrate and a nitrogen source in an aqueous medium;d2) inoculating said nutrient medium with a lactic acid or propionicacid producing microorganism;d3) incubating the inoculated nutrient medium under conditions favorableto the growth and/or metabolic activity of said lactic acid or propionicacid producing microorganism, for a period sufficient to produce a firstfermentation broth containing a lactate component and/or a propionatecomponent;d4) removing wet biomass from said first fermentation broth to obtain asupernatant; and, optionally,d5) subjecting said supernatant to further purification, with theproviso that the purification does not result in a level of the lactateand/or propionate component of more than 95 wt %, on a dry solids basis.

In a particularly preferred embodiment of the invention, step d1)comprises providing a nutrient medium comprising a carbon sourceselected from sugars such as glucose, sucrose, fructose, galactose andlactose and/or starch (hydrolysates) and step d2) comprises inoculatingsaid nutrient medium with lactic acid producing bacteria, preferablylactic acid bacteria belonging to the order Lactobacillales ormoderately thermophilic Bacillus species, such as Lactobacillus casei,Lactobacillus acidophilus, Lactobacillus delbrueckii, Lactobacillusparacasei, Lactobacillus helveticus, Lactococcus lactis, Lactococcusplantarum, Bacillus coagulans, Bacillus smithii and/or Bacillusthermoamylovorans.

In another particularly preferred embodiment of the invention, step d1)comprises providing a nutrient medium comprising a carbon sourceselected from glucose, lactose or lactate and step d2) comprisesinoculating said nutrient medium with propionic acid producing bacteria,in particular bacteria from the genus propionibacterium, such asPropionibacterium freudenreichii, Propionibacterium shermanii,Propionibacterium acidipropionici, Propionibacterium thoenii and/orPropionibacterium jensenii.

As stated above, in a preferred process a step d4) is performedcomprising removing wet biomass and other solid particles from thefermentation broth to obtain a supernatant, which can be used as theliquid fermentation product according to the invention.

The process may optionally comprise a step d5) comprising subjecting thesupernatant to further purification, with the proviso that thepurification does not result in a level of the lactate or propionatecomponent of more than 97 wt % on a dry solids basis, preferably it doesnot result in a level of the lactate or propionate component of morethan 96 wt % on a dry solids weight basis, most preferably it does notresult in a level of the lactate or propionate component of more than 96wt % on a dry solids weight basis. In a preferred embodiment of thepresent invention, a process as defined herein before is provided,wherein the supernatant as separated from the wet biomass in step d4) isnot subjected to a processing step wherein dissolved or non-dissolvedsolid matter is removed.

In an embodiment of the invention, step d) comprises the additional stepd6) of concentrating the ferment obtained in step d4) or d5), to aconcentrate comprising a dry solids level of up to 80 wt %, preferably45-75 wt %, more preferably 50-70 wt %, most preferably 55-65 wt %.

As will be appreciated by those skilled in the art, it is a particularadvantage of the present invention that blends of vinegar and other foodingredients can be produced having high concentrations of acetate/aceticacid. Hence, in one embodiment of the invention, a process as definedherein before is provided, wherein the food preservation productobtained after step e) has a final total concentration of acetate andacetic acid of above 10% (w/w), preferably above 20% (w/w), morepreferably above 25%, even more preferably above 30%.

Furthermore, in one embodiment of the invention, a process as definedherein before is provided, wherein the food preservation productobtained after step e) has a pH value, when diluted with water to a 10%(w/w) dry solids level, within the range of 5-9, more preferably withinthe range of 5.5-8, most preferably within the range of 6-7.

An aspect of the invention concerns the liquid compositions obtainableby the processes as defined herein.

Hence, in an aspect of the invention, a concentrated neutralized vinegaris provided with a total dry matter content of at least 50% (w/w), e.g.at least 50.1% (w/w); at least 50.5% (w/w); at least 51% (w/w); or atleast 52% (w/w). In a particularly preferred embodiment of the inventionthe concentrated neutralized vinegar has a total dry matter content ofat least 55% (w/w), even more preferably at least 60% (w/w), andcomprising potassium cations in an amount of at least 50 (mol) % of thetotal amount of cations present, more preferably at least 60 (mol) %,more preferably at least 70 (mol) %, more preferably at least 80 (mol)%, most preferably at least 90 (mol) %.

Also provided is a concentrated neutralized vinegar with a total aciditybased on acetic acid of at least 500 mmol per 100 ml., more preferablyat least 550 mmol per 100 ml, most re preferably at least 600 mmol per100 ml, and comprising potassium cations in an amount of at least 50(mol) % of the total amount of cations present, more preferably at least60 (mol) %, more preferably at least 70 (mol) %, more preferably atleast 80 (mol) %, most preferably at least 90 (mol) %.

Also provided is a concentrated neutralized vinegar with a total aciditybased on acetic acid of at least 31% (w/w), preferably at least 34%(w/w), more preferably at least 37% (w/w), and comprising potassiumcations in an amount of at least 50 (mol) % of the total amount ofcations present, more preferably at least 60 (mol) %, more preferably atleast 70 (mol) %, more preferably at least 80 (mol) %, most preferablyat least 90 (mol) %.

Also provided is a concentrated neutralized vinegar comprising at least50% (w/w) of potassium actetate, preferably at least 55% (w/w), morepreferably at least 60% (w/w).

The above described concentrated neutralized vinegars preferably have adegree of neutralization of at least 50%, more preferably at least 60%,more preferably at least 70%, more preferably at least 80%, morepreferably at least 90%, more preferably at least 95% and mostpreferably at least 99%

The above described concentrated neutralized vinegars preferably have apH value within the range of 5-9 more preferably 5.5-8.0, mostpreferably 5.8-7.5.

An aspect of the invention concerns a liquid food preservation productwhich is essentially a mixture of a concentrated neutralized vinegar asdescribed herein before and a standard non-neutralized vinegar.

Hence, a liquid food preservation product is provided, comprisingvinegar and/or neutralized vinegar, having a total acidity based onacetic acid of at least 25% (w/w), preferably at least 27.5% (w/w), morepreferably at least 30% (w/w) and a free acidity based on acetic acidwithin the range of 3.5-10% (w/w), preferably within the range of4.0-6.0% (w/w), most preferably within the range of 4.2-5.5% (w/w) andcomprising potassium cations in an amount of at least 50 (mol) % of thetotal amount of cations present in the liquid food preservation productmore preferably at least 60 (mol) %, more preferably at least 70 (mol)%, more preferably at least 80 (mol) %, most preferably at least 90(mol) %.

The above described liquid food preservation products preferably have apH value within the range of 5-9 more preferably 5.5-8, most preferably5.8-7.5.

The above described food preservation products preferably have a degreeof neutralization of at least 50%, more preferably at least 60%, morepreferably at least 70%, more preferably at least 80%, most preferablyat least 90%.

An aspect of the invention concerns a liquid food preservation productwhich is a mixture of a concentrated neutralized vinegar and acomposition comprising a lactate component, a proprionate componentand/or a citrate component as described herein before.

Hence, a liquid food preservation product is provided having a totalacidity of at least 32% (w/w), preferably at least 33% (w/w), morepreferably at least 35% (w/w), even more preferably at least 37% (w/w)and having a total acidity based on acetic acid of at least 5% (w/w),preferably at least 6%, preferably at least 7%, more preferably at least8%, more preferably at least 9%, even more preferably at least 10%, evenmore preferably at least 11% (w/w).

The above described liquid food preservation products preferablycomprise one or more components selected from lactate, propionate andcitrate. In a preferred embodiment of the invention, the (w/w) ratio ofacetic acid to other organic acids is at least 16%, more preferably atleast 19%, most preferably at least 22%, most preferably 25%.

The above described liquid food preservation products preferably have apH value within the range of 5-9 more preferably 5.5-8, most preferably5.8-7.5.

The above described concentrated neutralized vinegars preferably have adegree of neutralization of at least 50%, more preferably at least 60%,most preferably at least 70%, e.g. within the range of 50-98%, withinthe range of 60-95%, or within the range of 65-90%.

In the above described liquid food preservation products preferably atleast 50 (mol) % of the total amount of cations present in the liquidfood preservation product are potassium cations, more preferably atleast 60 (mol) %, more preferably at least 70 (mol) %, more preferablyat least 80 (mol) %, most preferably at least 90 (mol) %. Foodpreservation products as defined here above can also be provided in dryform, typically by subjecting the liquid product to standard dryingprocesses, such as spray drying. Products accordingly obtained aretypically characterized by the presence of high (relative) amounts ofacetate as well as by the presence of high (relative) amounts ofpotassium cations.

Hence, a food preservative product in solid form is provided, comprisingpartially or completely neutralized acetic acid, wherein potassiumcations are present in an amount of at least 50 (mol) % of the totalamount of cations present, more preferably at least 60 (mol) %, morepreferably at least 70 (mol) %, more preferably at least 80 (mol) %,most preferably at least 90 (mol) %.

The above described food preservative product in solid form preferablycomprises one or more components selected from partially or completelyneutralized lactate, partially or completely neutralized propionate andpartially or completely neutralized citrate. In a preferred embodimentof the invention, the (w/w) ratio of acetate to other organic acids isat least 16%, more preferably at least 19%, most preferably at least22%, most preferably 25%. The above described food preservative productin solid form preferably has a pH value, when dissolved in water at a10% dry solids weight level, within the range of 5-9 more preferably5.5-8, most preferably 5.8-7.5.

The above described food preservative product in solid form preferablyhas a degree of neutralization of at least 50%, more preferably at least60%, more preferably at least 70%, more preferably at least 80%, mostpreferably at least 90%.

Other aspects of the present invention entail the treatment of a foodproduct by incorporating therein the concentrated neutralized vinegarand/or liquid food preservation products as described herein and/or byapplying the concentrated neutralized vinegar and/or liquid foodpreservation product to the surface of the food product. The treatmentof food processing equipment by applying to the surface thereof theconcentrated neutralized vinegar and/or liquid food preservationproducts as described herein is also envisaged.

In a preferred embodiment of the invention, said food product isselected from the group consisting of ready meals, soups, sauces, freshmeat, fresh poultry, fresh fish or seafood, fresh produce, cut produce,composite foods, dairy products, snacks, processed meat or poultryproducts, cooked meat or poultry products, salad dishes, pasta dishes,pizza's, lunch meals.

Typically, the method entails the incorporation of the concentratedneutralized vinegar and/or liquid food preservation products asdescribed herein in an amount sufficient to accomplish an improvement inthe product, preferably in relation to one or more of the following:

i) extended shelf-life of the food productii) reduced outgrowth, germination, sporulation and/or toxin formationof/by pathogenic microorganisms, especially Clostridium botulinum,Clostridium perfringens, Staphylococcus aureus, Listeria monocytogenesand/or Bacillus cereus in the food product;iii) enhanced protection of a food product against spoilage bypathogenic and non-pathogenic microorganisms, such as yeasts, moulds,fungi and/or bacteria;iv) reduced risk with a food product of foodborne diseases, foodborneillness and/or food poisoning.

As commonly understood by those skilled in the art, these effectsconstitute relative improvements, not absolute characteristics. Hence,the amount may be any amount that confers a noticeable effect in termsof one or more of the above criteria, as compared to a food product notcomprising the present preservative system (but otherwise identical).

In one preferred embodiment, the use entails the incorporation of thepreservative composition of this invention in the food product in anamount resulting in an acetate level, in the form of acetic acid and/orsalts thereof, of more than 10 ppm, preferably more than 100 ppm,preferably more than 250 ppm, preferably more than 500 ppm, preferablymore than 1000 ppm, preferably more than 2000 ppm, preferably more than3000 ppm, preferably more than 4000 ppm, preferably more than 5000 ppm,preferably more than 6000 ppm, most preferably more than 7000 ppm.

Also provided herein is the food product obtainable by the treatmentdescribed herein before.

Also provided herein, is the use of a composition as defined herein, forthe preservation of a food product selected from the group consisting ofready meals, soups, sauces, fresh meat, fresh poultry, fresh fish orseafood, fresh produce, cut produce, composite foods, dairy products,snacks, processed meat or poultry products, cooked meat or poultryproducts, salad dishes, pasta dishes, pizza's, lunch meals.

In a preferred embodiment of the invention, said use, as will beunderstood by those skilled in the art, has one or more of the followingpurposes/objectives/effects recited here above.

Also provided herein, is the use of a composition as defined herein, forimparting or enhancing organoleptic attributes in the food product.

In a preferred embodiment of the invention, a use as defined herein isprovided, wherein said organoleptic attribute is selected from the groupof saltiness, brothiness, acidity.

Thus, the invention has been described by reference to certainembodiments discussed above. It will be recognized that theseembodiments are susceptible to various modifications and alternativeforms well known to those of skill in the art.

Many modifications in addition to those described above may be made tothe structures and techniques described herein without departing fromthe spirit and scope of the invention. Accordingly, although specificembodiments have been described, these are examples only and are notlimiting upon the scope of the invention.

Furthermore, for a proper understanding of this document and in itsclaims, it is to be understood that the verb “to comprise” and itsconjugations is used in its non-limiting sense to mean that itemsfollowing the word are included, but items not specifically mentionedare not excluded. In addition, reference to an element by the indefinitearticle “a” or “an” does not exclude the possibility that more than oneof the element is present, unless the context clearly requires thatthere be one and only one of the elements. The indefinite article “a” or“an” thus usually means “at least one”.

All patent and literature references cited in the present specificationare hereby incorporated by reference in their entirety.

The following examples are offered for illustrative purposes only, andare not intended to limit the scope of the present invention in any way.

EXAMPLES Example 1: Preparation of a Neutralized Vinegar Concentrate

Vinegar 300 grain (Fleischmann), direct pH 2.2 is neutralized with a 50%KOH-solution to a pH of 8.5. The neutralized vinegar (dry mattercontent=31%) is evaporated in a falling film evaporator up to a drymatter content of 62% The composition of the neutralized vinegarconcentrate is given in the table below. The stability of theconcentrate was monitored by visual inspection on precipitation duringstorage at ambient temperature. The concentrate proved to fulfill thestability requirements for common industrial applications.

Example 2: Preparation of Concentrated Vinegar

A concentrated vinegar was prepared by adding 300 grain vinegar(Fleischmann), water and optionally 50% NaOH to the product as obtainedin example 1 The composition of the concentrated vinegar as compared toa commercially available product is given in the table below.

Concentrated Vinegar Based on Neutralized Vinegar Concentrate

Cane Concen- Concen- Concen- vinegar trated trated trated (IsoAge)vinegar 1 vinegar 2 vinegar 3 Recipe Neutralized vinegar 25.7 42.6 73.7concentrate (62% potassium acetate) [% w/w] Vinegar 300 grain [%) 52.839.2 12.1 NaOH 50% [%] 15.6 10.4 Water [%] 5.9 7.8 14.2 TotalComposition Acetic acid [%] 24.8 25 27.5 31.5 Na [%] 4.6 4.5 3.0 K [%]6.3 6.3 10.5 18.2 Dry matter [%] 35.5 36 41 49 pH direct 6.4 6.3 6.6 7.2Free acidity (as acetic 3 4 4 4 acid) [g/100 ml]

The products were found to be stable at ambient temperature; noprecipitation and/or crystallization occurred within a period of atleast one month. The products were tested on application in various foodproducts. It was established that the products of the invention hadequal performance, both in terms of preservative effect and impact onthe organoleptic properties, as the commercially available product. Theproducts of the invention however have the advantage of lower dosagelevels and improved microbiological stability of the preservativeproduct. Food products prepared with this product can have a clean labelthat mentions the presence of eg “natural vinegar”.

Example 3: Preparation of Preservative Products with Mixed Organic Acids

Neutralized vinegar concentrate prepared as according to example 1 wasmixed with lactic acid and propionic acid ferments in order to prepareproducts with a relatively high amount of vinegar. The recipes for andthe composition of the products is given in the table below.

Products Based on Neutralized Vinegar Concentrate and Lactic AcidFerments

Product 1 Product 2 Product 3 Recipe Lactic acid ferment 1 (49.2% 47.84lactic acid) [%] Lactic acid ferment 2 32.0 27.44 (96% lactic acid) [%]Neutralized vinegar concentrate 22.83 30.0 40.00 (62% potassium acetate)[%] KOH 50% [%] 29.33 38.0 32.56 Total 100 100 100 Composition Lacticacid [%] 23.5 30.7 26.3 Acetic acid [%] 8.7 11.4 15.2 Ratio lacticacid/acetic acid 2.71 2.69 1.73 Potassium [%] 15.8 20.6 21.2 Dry matter[%] 48 62.6 62.5

Products based on neutralized vinegar concentrate and propionic acidferments. The propionic acid ferments 1-4 differ with respect to thepropionic acid and lactic acid content due to variations in thedownstream processing process of these ferments. Processes to producethese types of ferments are well known in the art. The method describedin patent publication no. EP2224011, for example, is particularlysuitable in this regard.

Prod- Prod- Prod- Prod- Prod- uct 4 uct 5 uct 6 uct 7 uct 8 RecipePropionic acid ferment 83.26 1) [%] Propionic acid ferment 79.77 70.0 2)[%] Propionic acid ferment 70.0 3) [%] Propionic ferment 4) [%] 70.0Neutralized vinegar 16.74 20.23 30.0 30.0 30.0 concentrate (62%potassium acetate) [%] KOH 50% [%] Total 100 100 100 100 100 CompositionPropionic acid [%] 3.9 4.8 2.7 4.2 4.8 Acetic acid [%] 7.8 9.4 12.4 12.913.2 Lactic acid [%] 26.8 32.4 31.9 28.4 27.0 Sodium [%] 2.06 2.49 1.412.18 2.49 Potassium [%] 15.5 8.8 21.1 19.5 18.9 Dry matter [%] 57.4 69.270.1 68.3 67.7

The products of the invention have the advantage of lower dosage levelsand improved microbiological stability of the preservative product. Foodproducts prepared with these preservative products can have a cleanlabel that mentions the presence of eg “natural vinegar” and/or“cultured corn sugar”.

1.-16. (canceled)
 17. A process of producing neutralized vinegarconcentrate, comprising: (a) providing a liquid vinegar; (b) adding analkaline potassium compound to the liquid vinegar to produce aneutralized vinegar having a pH of at least 6; and (c) concentrating theneutralized vinegar to a dry solids level of above 50% (w/w) byevaporation.
 18. The process according to claim 17, wherein step (c)comprises heating of the neutralized vinegar to a temperature between20-120° C.
 19. The process according to claim 18, wherein theneutralized vinegar is heated to a temperature between 40-110° C. 20.The process according to claim 17, wherein the neutralized vinegar isconcentrated to a dry solids level of above 55% (w/v).
 21. The processaccording to claim 20, wherein the neutralized vinegar is concentratedto a dry solids level of above 60% (w/v).
 22. The process according toclaim 17, further comprising (d) cooling down the neutralized vinegar toa temperature between 0-35° C.
 23. A process of producing a liquid foodpreservation product, comprising: (a) providing a liquid vinegar; (b)adding an alkaline potassium compound to the liquid vinegar to produce aneutralized vinegar having a pH of at least 6; (c) concentrating theneutralized vinegar to a dry solids level of above 50% (w/w) byevaporation; and (d) combining the concentrated neutralized vinegar witha composition comprising one or more organic acids and/or organic acidsalts to obtain a liquid food preservation product.
 24. The processaccording to claim 23, wherein the composition comprises a liquid crudevinegar of 200-300 grain.
 25. The process according to claim 23, whereinthe composition comprises a lactate, a propionate, and/or a citratecomponent.
 26. The process according to claim 25, wherein thecomposition is obtainable by: (i) providing a nutrient medium comprisinga solution of a fermentable substrate and a nitrogen source in anaqueous medium; (ii) inoculating the nutrient medium with a lactic acidor propionic acid producing microorganism; (iii) incubating theinoculated nutrient medium under conditions favorable to the growthand/or metabolic activity of the lactic acid or propionic acid producingmicroorganism, for a period sufficient to produce a first fermentationbroth containing a lactate component and/or a propionate component; (iv)removing wet biomass from the first fermentation broth to obtain asupernatant; and, optionally, (v) subjecting the supernatant to furtherpurification, with the proviso that the purification does not result ina level of the lactate and/or propionate component of more than 95 wt %,on a dry solids basis.
 27. The process according to claim 23, whereinthe food preservation product has a final total concentration of acetateand acetic acid above 10% (w/w).
 28. The process according to claim 27,wherein the food preservation product has a final total concentration ofacetate and acetic acid above 20% (w/w).
 29. A product obtainable by theprocess as defined in claim
 17. 30. A concentrated neutralized vinegarwith a total acidity based on acetic acid of at least 500 mmol per 100 gand comprising potassium cations in an amount of at least 50 (mol) % ofthe total amount of cations present.
 31. A concentrated neutralizedvinegar comprising at least 50% (w/w) potassium actetate.
 32. Theconcentrated neutralized vinegar according to claim 31, comprising atleast 55% (w/w) potassium actetate.
 33. The concentrated neutralizedvinegar according to claim 32, comprising at least 60% (w/w) potassiumactetate.
 34. A liquid food preservation product, comprising vinegarand/or neutralized vinegar, having a total acidity based on acetic acidin excess of 25% (w/w) and a free acidity based on acetic acid of withinthe range of 3.5-10%, and comprising potassium cations in an amount ofat least 50 (mol) % of the total amount of cations present in the liquidfood preservation product.
 35. A liquid food preservation product,having a pH between 5 and 9, comprising (i) at least 5% vinegar and/orneutralized vinegar, and (ii) a lactate, propionate, and/or citratecomponent, the liquid food preservation product having a total acidityof at least 32% (w/w).